KR20190069438A - Methods of retarding curing in polyurethanes and compositions and articles made therefrom - Google Patents

Abstract

The process for the preparation of polyurethanes comprises reacting an active hydrogen-containing component; An organic isocyanate component that reacts with the active hydrogen-containing component; A metal catalyst, preferably metal acetylacetonate; And a catalyst inhibitor effective to inhibit gelation of the curable composition at a temperature of 55 DEG C for at least 4.7 minutes, preferably at least 5 minutes. Processing the curable composition at a first temperature without curing the curable composition; And curing the curable composition to provide the polyurethane.

Description

Methods of retarding curing in polyurethanes and compositions and articles made therefrom

The present invention relates generally to a process for the preparation of polyurethanes and to products made by the process for the preparation of said polyurethanes. The process for preparing the polyurethanes is useful for the production of solid polyurethanes and polyurethane foams and articles made therefrom.

Polyurethanes are generally formed from reactive mixtures comprising an organic isocyanate component and an active hydrogen-containing component that are substantially reactive with one another in the presence of a polyurethane-forming component, particularly a catalyst. The foamed polyurethane can be prepared by frothing or blowing such a reactive mixture.

Some prior art polyurethane processing is dependent on the use of ferric acetylacetonate catalysts. One disadvantage associated with the use of iron acetylacetonate as a catalyst in polyurethane reactions is the high catalytic activity at room temperature which can lead to an undesirably fast, i.e., premature cure of the reactive mixture. For example, if the polyurethane cure is too fast, polyurethane cure may occur during the movement and processing of the bulk material, which may reduce or inhibit material diffusion or cause phase separation, resulting in a lower quality foam.

Thus, there remains a need for a method of retarding cure in polyurethanes with improved physical properties.

The process for the preparation of polyurethanes comprises reacting an active hydrogen-containing component; An organic isocyanate component that reacts with the active hydrogen-containing component; A metal catalyst, preferably metal acetylacetonate; And a catalyst inhibitor effective to inhibit gelation of the curable composition at a temperature of 55 DEG C for at least 4.7 minutes, preferably at least 5 minutes. Processing the curable composition at a first temperature without curing the curable composition; And curing the curable composition to provide the polyurethane.

In addition, polyurethanes produced by the methods described above, and articles comprising the polyurethanes, are described herein.

The above and other features are exemplified by the following drawings and detailed description.

The following figures are exemplary embodiments and show the gel time of a curable urethane composition containing a catalyst inhibitor according to some embodiments of the present invention.

The inventors of the present invention have found a method of delaying, i.e. inhibiting, the curing of the curable urethane composition. Generally, such compositions include an active hydrogen-containing component, an organic isocyanate component that reacts with the active hydrogen-containing component, optionally a surfactant, a metal catalyst, and a catalyst inhibitor. Usually, the metal catalyst is metal acetylacetonate. Such catalysts can promote undesirably fast, i.e., early cure, of the curable polyurethane-forming composition even at room temperature (i.e., 25 ° C). In a key step of the present disclosure, curing of the curable urethane composition can be delayed, or premature curing can be inhibited in the presence of a catalyst inhibitor. Advantageously, delayed curing of the curable urethane composition permits sufficient time for material migration and material diffusion during polyurethane production. Another advantage is that delayed curing in the presence of a catalyst inhibitor produces a polyurethane, preferably a foamed polyurethane, having improved physical properties such as resistance to compression set. In another advantage of the present disclosure, the curing of the curable urethane composition can be delayed at temperatures above room temperature, for example at curing temperatures above the melting point of the active hydrogen-containing component.

Without being bound by theory, it is known that catalyst inhibitors can be used to retard or inhibit the usually reactive catalyst, i. E. Metal acetyl acetonate, at the higher temperatures needed to achieve proper mixing and casting of raw materials that are solid at room temperature. That is, the catalyst inhibitor provides heat latency that allows time for the required mixing, casting and other procedures, and inhibits harmful premature curing during processing at temperatures above the melting point of the raw material.

The catalyst inhibitor is usually at least one of? -Diketone,? -Diketoamide,? -Ketoester,? -Diester,? -Dinitrile,? -Dialdehyde,? -Ketoaldehyde, And a combination including one. Non-limiting examples of catalyst inhibitors include acetylacetone, dibenzoylmethane, 4,4,4-trifluoro-1-phenyl-1,3-butanedione, 3-butanedione, N, N-diethyl-acetoacetamide, benzoylacetone, dimethyl isobutylmalonate, diethyl isobutylmalonate 3-ethyl-2,4-pentanedione, 3-chloro-2,4-pentanedione, dimethylmalonate dimethyl malonate, diethyl malonate, malononitrile, 18-crown-6, or a combination comprising at least one of these. Preferably, the catalyst inhibitor comprises at least one of dibenzoylmethane, 4,4,4-trifluoro-1-phenyl-1,3-butanedione, N, N-diethyl-acetoacetamide, ≪ / RTI >

The amount of the catalyst inhibitor is in the range of 5 to 5000 mol%, preferably 20 to 2000 mol%, more preferably 50 to 1000 mol%, based on the total moles of the metal catalyst, for example, metal acetylacetonate, 100 to 1000 mole%.

The organic isocyanate component generally comprises a polyisocyanate having the formula Q (NCO) _i wherein "i" is an integer with an average value of at least 2 and Q is an organic radical having valence of "i ". Q can be a substituted or unsubstituted hydrocarbon group (e.g., alkanes or aromatic groups of suitable valencies). Q is a group having the formula Q ¹ -ZQ ¹ wherein Q ¹ is an alkylene or arylene group and Z is -O-, -OQ ¹ -S, -CO-, -S-, -SQ ¹ -S -, -SO- or -SO ₂ - a. Exemplary isocyanates include hexamethylene diisocyanate, 1,8-diisocyanato-p-methane, xylyl diisocyanate, diisocyanate, Toluene / toluene diisocyanate, including diisocyanatocyclohexane, phenylene diisocyanates, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, and crude tolylene diisocyanate, Toluene diisocyanate, bis (4-isocyanatophenyl) methane, chlorophenylene diisocyanate, diphenylmethane-4,4'-diisocyanate (4,4'- Diphenylmethane diisocyanate, or MDI) and its adducts, naphthalene-1,5-diisocyanate, triphenylmethane-4,4 ', 4 "-triisocyanate Polymeric isocyanates such as triphenylmethane-4,4 ', 4 "-triisocyanate, isopropylbenzene-alpha-4-diisocyanate and polymethylene polyphenylisocyanate, A prepolymer comprising at least one of the foregoing, a pseudopolymer comprising at least one of the foregoing, or a combination comprising at least one of these isocyanates.

Q is a polyurethane group having a valence of "i", and Q (NCO) _i is a composition known as a prepolymer. These prepolymers are formed by reacting an excess of polyisocyanate with an active hydrogen-containing component, in particular a polyhydroxyl-containing material, or the polyol described below in the stoichiometric composition presented herein. Usually, for example, the polyisocyanate is used in an excess of 30 to 200 percent stoichiometric composition, and the stoichiometric composition is based on the equivalents of the isocyanate groups per equivalent of hydroxyl in the polyol. The amount of polyisocyanate used will vary slightly depending on the nature of the polyurethane being prepared.

The active hydrogen-containing component may comprise a polyether polyol or a polyester polyol. Exemplary polyester polyols include polycondensation products of polyols and dicarboxylic acids or ester-forming derivatives thereof (e.g. anhydrides, esters and halides), polylactone polyols obtained by ring-opening polymerization of lactones in the presence of polyols, A polycarbonate polyol obtained by the reaction of an ester with a polyol, and a castor oil free polyol. Exemplary derivatives of dicarboxylic acids and dicarboxylic acids useful for producing polycondensed polyester polyols include aliphatic or alicyclic dicarboxylic acids such as glutaric acid, adipic acid, sebacic acid, fumaric acid and maleic acid; Dimeric acid; Aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid; Tribasic or higher functional polycarboxylic acids such as pyromellitic acid; And anhydrides and secondary alkyl esters such as maleic anhydride, phthalic anhydride and dimethyl terephthalate.

The additional active hydrogen-containing component is a polymer of a cyclic ester. The preparation of cyclic ester polymers from at least one cyclic ester monomer is described in U.S. Pat. Patent No. 3,021,309-3,021,317; 3,169,945; And 2,962,524, which are incorporated herein by reference. Exemplary cyclic ester monomers include? -Valerolactone; ? -caprolactone; Zeta-enantholactone; And monoalkyl-valerolactones (e.g., monomethyl-, monoethyl-, and monohexyl-valerolactone). Generally, the polyester polyol is selected from the group consisting of caprolactone based polyester polyols, aromatic polyester polyols, ethylene glycol adipate based polyols, A combination comprising at least one, and in particular a polyester polyol made from epsilon -caprolactone, i.e., polycaprolactone, adipic acid, phthalic anhydride, terephthalic acid and / or terephthalic acid.

The polyether polyol may be a water or polyhydric organic component of an alkylene oxide (e.g., ethylene oxide, propylene oxide, and the like and a combination comprising at least one of them) (e.g., ethylene glycol, propylene glycol , Trimethylene glycol, 1,2-butylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,2-hexylene glycol, Cyclohexene-1,1-dimethanol, 4-methyl-3-cyclohexene-1,1-dimethanol, 3-methylene-1,5 (2-hydroxyethoxy) -1-butanol, 5- (2-hydroxypropoxy) -1-pentane (2-hydroxypropoxy) -2-octanol, 3-allyloxy-1,5-pentanediol, 2-allyloxy Methyl-2-methyl-1,3-propanediol, [4,4-pentyloxy) -methyl] -1,3- , 2,2'-diisopropylidenebis (p-phenyleneoxy) diethanol, glycerol, 1,2,6-hexanetriol Trimethylolethane, 1,1,1-trimethylol propane, 3- (2-hydroxyethoxy) -1,2-propanediol, 3- (2-hydroxypropyl) Phenoxy) -1,2-propanediol, 2,4-dimethyl-2- (2-hydroxyethoxy) -methylpentanediol-1,5; Tris [2-hydroxyethoxy] methyl] -ethane, 1,1,1-tris [2-hydroxypropoxy) -methyl] propane, diethylene glycol, dipropylene glycol, pentaerythritol Alpha-hydroxyalkyl glucosides, novolak resins, phosphoric acid, benzenephosphoric acid, polyphosphoric acids such as tripolyphosphoric acid and tetrapolyphosphoric acid, tertiary condensation products, such as, for example, sorbitol, sucrose, lactose, alpha-methyl glucoside, alpha-hydroxyalkyl glucoside, Ternary condensation product, etc., and combinations comprising at least one of these). The alkylene oxide used in the preparation of the polyoxyalkylene polyol usually has 2 to 4 carbon atoms. Mixtures of propylene oxide and propylene oxide with ethylene oxide are preferred. The polyols listed above may be used as the active hydrogen component.

A useful class of polyether polyols is generally represented by the formula R [(OCH _n H _2n ) _z OH] _{a wherein} R is hydrogen or a polyvalent hydrocarbon radical; " a "is an integer the same as the valence of R, and in each case" n "is an integer (preferably 3) comprising 2 to 4 and in each case" z "Lt; RTI ID = 0.0 > 15 < / RTI > Preferably, the polyether polyol comprises a mixture of at least one of dipropylene glycol, 1,4-butanediol, and 2-methyl-1,3-propanediol and the like.

Another type of active hydrogen-containing material that can be used is a polymer polyol composition obtained by polymerizing ethylenically unsaturated monomers in a polyol as described in U.S. Patent No. 3,383,351. Exemplary monomers for making such compositions include acrylonitrile, vinyl chloride, styrene, butadiene, vinylidene chloride, and other ethylenically unsaturated monomers. The polymer polyol composition may contain from 1 weight percent (wt%) to 70 wt%, or more preferably from 5 to 50 wt%, even more preferably from 10 wt% to 40 wt% of monomers polymerized in the polyol , And the weight percent is based on the total weight of the polyol. Such a composition may be a free radical polymerization catalyst such as peroxides, persulfates, percarbonates, perborates, azo compounds, and combinations comprising at least one of the foregoing. Lt; RTI ID = 0.0 > 40 C < / RTI > to < RTI ID = 0.0 > 150 C. < / RTI >

The active hydrogen-containing component may also be a polyhydroxyl-containing compound, such as hydroxyl-terminated polyhydrocarbons (U.S. Patent No. 2,877,212); Hydroxyl-terminated polyformals (U.S. Patent No. 2,870,097); Fatty acid triglycerides (U.S. Patent Nos. 2,833,730 and 2,878,601); Hydroxyl-terminated polyesters (U.S. Patent Nos. 2,698,838, 2,921,915, 2,591,884, 2,866,762, 2,602,776, 2,729,618, 2,779,689, 2,811,493, 2,621,166, and 3,169,945); Hydroxymethyl-terminated perfluoromethylenes (U.S. Patent Nos. 2,911,390 and 2,902,473); Hydroxyl-terminated polyalkylene ether glycols (U.S. Patent No. 2,808,391; British Patent No. 733,624); Hydroxyl-terminated polyalkylene arylene ether glycols (U.S. Patent No. 2,808,391); And a hydroxyl-terminated polyalkylene ether triol (U.S. Patent No. 2,866,774).

Chain extenders and cross-linking agents may be included in the active hydrogen-containing component. Exemplary chain extenders and crosslinkers include low molecular weight diols such as alkanediols and dialkylene glycols, and / or polyhydric alcohols, preferably triols and tethols of molecular weight 80 to 450 tetrol). Examples of the chain extender include ethylene glycol, diethylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, cyclohexanedimethanol, hydroquinone bis (2-hydroxyethyl) ether and the like. Combinations comprising at least one of these may be used. The chain extenders and cross-linking agents may be used in amounts of from 0.5 to 20% by weight, preferably from 10 to 15% by weight, based on the total weight of the polyol component.

In some embodiments, the prepolymer composition for making the foam may in fact be in accordance with Japanese Patent Publication No. 53-8735. The polyols preferably used have respective repeating units (referred to as "units") of PO (propylene oxide) and / or PTMG (tetrahydrofuran to which ring-opening polymerization is applied). In certain embodiments, the amount of EO (ethylene oxide; (CH ₂ CH ₂ O) _n ) is minimized to improve the hygroscopicity of the foam. Preferably, the percentage of EO units (or the ratio of EO units) in the polyol may be 20% or less. For example, when the polyol used is simply a PO-unit and an EO-unit, this polyol is set within the range of [PO units]: [EO units] = 100: 0 to 80:20. Percentage of EO unit is called "EO content". In some embodiments, the polyol component comprises one or a combination of ethylene oxide-capped polyether oxide diols ranging in molecular weight from 2000 to 3500.

The polyols may have hydroxyl numbers that vary over a wide range. Generally, the hydroxyl number of the polyol comprising other crosslinking additives can be from 28 to 1,000 or more, or more preferably from 100 to 800 when used. The hydroxyl number is defined as the number of milligrams of potassium hydroxide required for complete neutralization of the hydrolysis product of a fully acetylated derivative produced from one gram of polyol or polyol mixture with or without other crosslinking agents. In addition, the hydroxyl number can be defined by the following equation:

In the equation, OH is the hydroxyl number of the polyol,

f is the average functionality of the polyol, which is the average number of hydroxyl groups per molecule, and

M _W is the average molecular weight of the polyol.

In an embodiment, a catalyst inhibitor is added to the active hydrogen-containing component. In some instances, the catalyst inhibitor, i. E., Dissolves in the live hydrogen-containing component prior to formation. Usually, the catalyst inhibitor is added prior to processing.

The exact polyols or polyols applied depend on the end use of the polyurethane foam. In particular, changes in the polyol component can achieve a wide range of moduli and toughness. The molecular weight and the hydroxyl number are appropriately selected to produce a flexible foam. Polyols or polyols, including cross-linking additives, when used, preferably have a hydroxyl number of 28 to 1250 or greater when applied to flexible foam formulations. These limitations are not intended to be limiting, but merely illustrate the many possible combinations of polyols that can be used.

Many metal catalysts including metal acetylacetone may be used. Exemplary catalysts include aluminum acetyl acetonate, barium acetyl acetonate, cadmium acetyl acetonate, calcium acetyl acetonate, cerium (III) acetylacetonate, (II) acetylacetonate, iron (II) acetylacetonate, cobalt (II) acetylacetonate, copper (II) acetylacetonate, indium acetylacetonate, iron Manganese (II) acetylacetonate, manganese (III) acetylacetonate, neodymium acetyl acetonate, nickel (II) acetylacetonate, lanthanum acetylacetonate, lead Acetonate, palladium (II) acetylacetonate, potassium acetyl acetonate, But are not limited to, sodium acetylacetonate, sodium acetyl acetonate, terbium acetyl acetonate, titanium (IV) acetylacetonate, vanadium (V) acetylacetonate, yttrium acetylacetonate yttrium acetyl acetonate, zinc (II) acetylacetonate, zirconium (IV) acetylacetonate, or a combination comprising at least one of the foregoing, preferably iron (III) acetylacetonate.

The amount of catalyst present can be from 0.001 to 0.5 weight percent (wt.%), Preferably from 0.005 to 0.1 wt.%, More preferably from 0.006 to 0.02 wt.%, Based on the weight of the curable composition.

If present, the molar ratio of the metal catalyst to the catalyst inhibitor, for example acetylacetone or dibenzoylmethane, for example metal acetylacetonate, is from 5: 1 to 1:20, preferably from 3: 1 to 1: : 10, more preferably from 1: 1 to 1:10, and still more preferably from 1: 3 to 1: 6. In embodiments, the molar ratio of metal acetylacetonate to catalyst inhibitor is 1: 6.

Once the foam is formed, various surfactants can be used including a mixture of surfactants to stabilize the polyurethane foam before curing. SiO ₂ (silicate) units and (CH ₃ ) ₃ SiO _{0 wherein} the molar ratio of silicate to trimethylsiloxy unit is from 0.8: 1 to 2.2: 1, or more preferably from 1: 1 to 2.0: 1 _. Organosilicone surfactants such as copolymers essentially consisting of ₅ (trimethylsiloxy) units are particularly useful. Other organosilicon surfactant stabilizers are partially cross-linked siloxane-polyoxyalkylene block copolymers and mixtures thereof, siloxane blocks and polyoxyalkylene blocks may be attached to the carbon by silicon, (oxygen to carbon) bonds. The siloxane block contains a hydrocarbon-siloxane group and has an average valence of at least 2 per block that is mixed into the bond. At least a portion of the polyoxyalkylene blocks comprise oxyalkylene groups and are polyvalent, i.e. have a valence of at least 2 of carbon-per-block and / or carbon-based oxygen to be mixed into the bond. Any remaining polyoxyalkylene blocks comprise oxyalkylene groups and are monovalent, i.e. have only one valence of carbon and / or carbon-based oxygen per block that is mixed into the bond. Additional organopolysiloxane-polyoxyalkylene block copolymers include those described in U.S. Patent Nos. 2,834,748, 2,846,458, 2,868,824, 2,917,480, and 3,057,901. Also, a combination comprising at least one of these surfactants may be used. The amount of organosilicon polymer used as the foam stabilizer may vary within wide limits, for example from 0.5% to 10% by weight, or preferably from 1.0 to 6.0% by weight, based on the amount of active hydrogen component.

The curable composition further comprises one or more other components or additives such as a flame retardant, filler, inhibitor, dispersion aid, adhesion promoter, dye, plasticizer, heat stabilizer, pigment, antioxidant, epoxy compound or combinations comprising at least one of these can do. Typically, the amount of additive used is from 0.5 to 40% by weight, preferably from 5 to 40% by weight, more preferably from 10 to 30% by weight, based on the total weight of the polyurethane composition.

Examples of flame retardants include graphite-containing flame retardants, phosphorus-containing flame retardants, halogen-containing flame retardants such as aromatic brominated or chlorinated flame retardants, or combinations comprising at least one of the foregoing. Examples of specific flame retardants include tribromoneopentyl alcohol, tris (2-chloroisopropyl) phosphate, tris (dichloropropyl) phosphate, chlorinated alkyl phosphate esters, halogenated aryl esters / aromatic phosphates But are not limited to, halogenated aryl esters / aromatic phosphate blends, pentabromobenzyl alkyl ethers, brominated epoxies, alkylated triphenyl phosphate esters, Combinations.

Processing the curable composition occurs at a first temperature and does not cure the curable composition. Usually, processing of the curable composition occurs at a first temperature of 120 ° C, preferably 40 to 120 ° C, more preferably 50 to 120 ° C. In some instances, processing includes moving the curable composition, molding the curable composition, or a combination comprising at least one of the foregoing.

Curing takes place at cure time. Usually, this cure time is at least 50% longer than the cure time of the same curable composition without catalyst inhibitor, as measured by a gel time test at 70 < 0 > C. Preferably, the cure time according to the gel time test at 70 占 폚 is at least 100% longer than the cure time of the same curable composition without the catalyst inhibitor, as measured by the gel time test at 70 占 폚, Is at least 200% longer. In some instances, the cure time is greater than 2 minutes, preferably greater than 3 minutes, and more preferably greater than 5 minutes as measured by gel time testing at 70 占 폚.

Curing can occur at temperatures above room temperature. The temperature higher than the room temperature can be suitably selected when the melting point of the urethane composition is larger than the room temperature. For example, the curing temperature may be from 30 to 100 占 폚 or from 40 to 80 占 폚, or from 55 to 70 占 폚. In embodiments, the curing takes place at a temperature at which the active-hydrogen-containing component is in a molten state, i. E. Above the melting point of the active-hydrogen-containing component. In some embodiments, a cure temperature of 30 to 100 DEG C from shear may occur during mixing of the components in a high shear mixer.

In some embodiments, the curing comprises raising the temperature of the curable composition to a second temperature effective to cure the curable composition. In this example, the second temperature may be 40 to 120 占 폚, preferably 60 to 120 占 폚, more preferably 60 to 120 占 폚.

In some instances, the catalyst inhibitor is effective at inhibiting gelation of the curable composition at 70 DEG C for at least 2 minutes, preferably at least 3 minutes. In some embodiments, the inhibitor is effective to provide a gel time at 70 DEG C that is 3 times longer, preferably at least 3.5 times longer, more preferably at least 4 times longer than the gel time of the same curable composition without catalyst inhibitor.

The polyurethane composition may be a polyurethane foam. As used herein, "foam" refers to a material having a cellular or porous structure. A "cellular foam" refers to a material in which at least a portion of the cells extend through the layer. Suitable foams have a density of less than 65 pcf (lb / ft ³ , pounds per cubic foot), preferably 55 pcf or less, more preferably 52 pcf or less, for example, 5 to 52 pcf. The foam may have a void volume of 13 to 99%, preferably 30% or more, based on the total volume of the polymer foam. In some embodiments, the foam has a density of 5 to 30 pcf (80 to 481 kg / m ³ ), a 25% compressive force deflection (CFD) of 0.5 to 450 lb / in ² (0.003 to 3.10 N / mm ² ) The compressive strain at 70 deg. C (70 deg. C) is less than 10%, and the compressive strain at 70 deg. C (21 deg. C) is less than 10%, preferably less than 5%.

The polyurethane foam may be prepared by frothing or chemically or physically blowing, or a combination comprising at least one of these. For example, the curable composition may be mechanically pruned and then cured, e.g., formed into a sheet-like shape. In embodiments, the polyurethane foam is a foam that is blown or blown with water. Preferably, the foam is a mechanically-frothed foam.

Any mechanically-prided polyurethane composition-forming curable composition may be used in the practice of the method. In particular, U.S. Patent Nos. 3,706,681 for the disclosure of mechanically-prilled polyurethane-forming mixtures and components (e. G., Surfactants) 3,755,212; 3,772,224; 3,821,130; 3,862,879; 3,947,386; 4,022,722; 4,216,177 and 4,692,476, the entire disclosures of which are incorporated herein by reference in their entirety. It will also be appreciated that any other mechanically-prided polyurethane-forming mixture may be used.

As described in detail in U.S. Patent No. 4,216,177, the mechanically-prilled polyurethane-forming mixture is mechanically beating a mixture of inert gas such as air into a mixture in a standard mixing apparatus such as a SKG mixer, Hobart mixer or Oakes mixer, . Thus, the mixture is mechanically prilled to form a substantially chemically stable froth and is readily operable at ambient temperatures between 15 ° C and 30 ° C, but is structurally stable. The consistency of these bubbles can be similar to that of aerosol-dispersed shaving creams. In embodiments, the foam is readily operable at a temperature of 70-100 < 0 > C.

When the foam is blown, the various blowing agents may be used in a prepolymer composition comprising a chemical or physical blowing agent. Chemical blowing agents include, for example, water and chemical compounds that decompose under certain conditions, for example, in high gas yields within a narrow temperature range. Preferably, the decomposition product is not foamed or has no discoloring effect on the foamed product. Exemplary chemical blowing agents include, but are not limited to, water, azoisobutyronitrile, azodicarbonamide (i.e., azo-bis-formamide) and barium azodicarboxylate; Substituted hydrazines such as diphenylsulfone-3,3'-disulfohydrazide, 4,4'-hydroxy-bis- (benzene sulfohydrazide), trihydrazinotriazine, , And aryl-bis- (sulfohydrazide)); (For example, p-tolylene sulfonyl semicarbazide, d4,4'-hydroxy-bis- (benzenesulfonyl semicarbazide)); Triazoles (e. G., 5-morpholyl-l, 2,3,4-thiatriazole); N-nitroso compounds (e.g., N, N'-dinitrosopentamethylenetetramine and N, N-dimethyl-N, N'-dinitrosophthalamide); Benz photo (e. G., Isatoic anhydride); And mixtures comprising at least one of these, such as a sodium carbonate / citric acid mixture.

The amount of chemical blowing agent may vary depending on the formulation and the desired foam density. Generally, the chemical blowing agent may be used in an amount of 0.1 to 10% by weight based on the total weight of the prepolymer composition. When water is used as the blowing agent (e.g., in an amount of from 0.1 to 8% by weight based on the total weight of the prepolymer composition), it may generally be desirable to control the cure reaction by selectively applying the catalyst.

In addition, physical blowing agents can be used. Such blowing agents may be selected from a wide variety of materials including hydrocarbons, ethers, esters (including partially halogenated hydrocarbons, ethers, and esters), etc., and combinations comprising at least one of these. Exemplary physical blowing agents include CFC's (chlorofluorocarbons) such as 1,1-dichloro-1-fluoroethane, 1,1-dichloro-2,2,2-trifluoro-ethane, Fluoromethane, and 1-chloro-1,1-difluoroethane; FC's (fluorocarbons) such as 1,1,1,3,3,3-hexafluoropropane, 2,2,4,4-tetrafluorobutane, 1,1,1,3,3, 3-hexafluoro-2-methylpropane, 1,1,1,3,3-pentafluoropropane, 1,1,1,2,2-pentafluoropropane, 1,1,1,2,3 - pentafluoropropane, 1,1,2,3,3-pentafluoropropane, 1,1,2,2,3-pentafluoropropane, 1,1,1,3,3,4-hexafluoro Butane, 1,1,1,3,3-pentafluoropropane, 1,1,1,4,4,4-hexafluorobutane, 1,1,1,4,4-pentafluoropropane, 1,1,2,2,3,3-hexafluoropropane, 1,1,1,2,3,3-hexafluoropropane, 1,1-difluoroethane, 1,1,1,2 - tetrafluoroethane, and pentafluoroethane; FE's (fluoroethers) such as methyl-1,1,1-trifluoroethyl ether and difluoromethyl-1,1,1-trifluoroethyl ether; Hydrocarbons such as n-pentane, isopentane, and cyclopentane; And combinations comprising at least one of the foregoing. As a chemical blowing agent, the physical blowing agent is used in an amount sufficient to provide the desired bulk density of the resulting foam. The physical blowing agent may be used in an amount of 5 to 50% by weight of the prepolymer composition, or more preferably 10 to 30% by weight of the prepolymer composition.

After loading or blowing, the composition (referred to as "foam" for convenience) is moved at a controlled rate through a hose or other conduit located on a moving support. The support may have a planar or textured surface on which the foam is located. The support can be played out from the supply roll and pulled by the roll to pass through various stations in the system and can generally be finally rewound on a take-up roll. The support may be a release substrate such as stainless steel, or a polymer or other material, such as a release paper, a thin sheet of metal. The support may be coated with a material such as a urethane film that is transferred to the surface of the foam or may have a release coating. If desired, the support material may be a fibrous or other material substrate that causes it to be rewound on the take-up roll, to form a part of the final product, instead of being separated from the foam, and to be laminated. Alternatively, the support substrate may be a conveyor belt.

Since the support is moved with the foam located thereon, the foam may be dispersed into a layer of desired thickness by a doctoring blade or other suitable dispersing device. Table doctor blades or other more complex dispersing devices, such as a knife over roller coater or a simple knife on three or four roll reversible coaters. The doctor blade can disperse the material to a desired thickness, for example, a thickness of 0.01 to 100 mm.

The assembly of the release support and the gauged layer of the foam is then transferred to a heating zone consisting of spaced lower and upper heating platens. The platens may be parallel and have equal spacing therebetween along their entire length, or they may be weakly classified as an inlet to an outlet. The heating platen is heated by an electrical heating element that can be controlled separately to provide incremental heating. The platen may simply be a platen, or each may be comprised of two or more separate platens, some of which may have separate electrical heating elements to provide different temperature ranges.

There is a direct conduction heating of the foam layer from the lower platen in direct contact with the release paper because the release of the plaming material and assembly of the gauge layer pass through the heating zone between the platens. In addition, the top heating platen can be spaced as close as desired above the top surface of the foam layer, so long as it is not in contact with the uncovered top layer of material, thereby providing substantial amounts of radiant heat and some convective heat to the foam sheet. During this heating step, the foamed material is cured by the acceleration of curing to produce a cured polyurethane foam. The temperature of the platen is maintained in the range of 90 ° C to 230 ° C depending on the composition of the foamed material. These platens can be maintained at the same or non-identical temperature depending on the particular characteristics of the curing process that they are intended to perform. For example, the differential temperature can be established for the purpose of forming an integral skin on one layer of foam or laminating a relatively heavy layer on the foam.

After the assembly has been heated, it may be passed to a cooling zone that is cooled by any suitable cooling device, such as a fan. The release can be removed and the foam wound on a roll for storage or used as needed. The polyurethane foam produced by the process described will be a foam sheet of uniform gauge. In addition, the density of the finished product is relatively uniform since conduction and radiant heating during the curing process provides a relatively uniform heat distribution across the foam sheet.

In embodiments, the polyurethane foam has at least one of the following properties: a density of 40 to 900 kg / m ³ , preferably 100 to 850 kg / m ³ , measured according to ASTM 3574; A 25% compressive force bias of 0.5 to 450 lb / in ² (0.003 to 3.10 N / mm ² ); Compressive strain at 158 ° F, measured according to ASTM 3574, is less than 10%, compressive strain at 70 ° F (21 ° C) is less than 10%, preferably less than 5%.

The curable composition may also be molded into articles, for example by casting, compression, molding, blow-molding, and the like. Such molding is preferably performed by casting or molding. The article may be any one that uses a polyurethane in general, such as protective packaging, insulation, gel pads, printing rollers, electronic components, straps, bands, cars, furniture, bedding, carpet underlay, shoe inserts, textile coatings .

The present invention is further illustrated by the following examples.

Example

The formulations shown in Table 1 are used as exemplary curable compositions for forming polyurethane and are based on the formulations shown in US 2002/01282420, US 6559196, and US6635688. The catalyst in each formulation is ferric acetylacetonate, which is provided in a 3: 1 molar ratio of acetylacetonate to the catalyst, in preacetyl acetonate. Apart from the control without additional cure inhibitor, each example contained the indicated cure inhibitor. All catalyst inhibitors were added to provide 1.32 x 10 < ^-6 > moles of inhibitor.

(Table 1) Polyurethane formulation

* Shipped in the listed quantities

Each example was tested to determine the gel time at 55 캜 and 70 캜 as follows. All raw materials were mixed and stored at the desired test temperature. In particular, all but the isocyanates were mixed and placed in a 400 mL Flack Tek Speed Mixer beaker with a screw top. The isocyanate was accurately measured and added to the beaker quickly with a syringe. The beaker was quickly placed in a Flack Tek mixing chamber and mixed at 1250 rpm for 6 seconds, then at 2100 rpm for 6 seconds, and finally at 2500 rpm for 12 seconds. Upon completion of the mixing, the timer was started and the contents of the beaker were poured into a test cup of the Gardner Co. gel time tester at the cup temperature set to match the desired reaction temperature. The gel timer was switched on and the stopwatch was stopped to record the total gel time of the system, while spinning until the stop point was reached. All mixing time and delivery time were kept as consistent as possible.

The results of the gel time test are summarized in Table 2 and shown in FIG.

(Table 2)

The results in Table 2 and Figure 1 show that the gel time decreases with increasing temperature. The use of acetylacetone as a cure inhibitor showed a significant increase in gel time compared to no addition of a compound such as dimethyl malonate or inhibitor at 55 < 0 > C. The gel time using DBM and TPB as inhibitors was further improved.

However, at 70 캜, the gel time of the acetylacetonate was in the same order as the curing inhibitor was not used at 55 캜. This fast gel time indicates that acetylacetone is virtually less effective as a cure inhibitor at higher temperatures. In contrast, the gel time of DBM and TPB indicates that these inhibitors are effective at higher processing temperatures.

The present invention is further illustrated by the following embodiments.

Embodiment 1: A method for producing a polyurethane, comprising the steps of: mixing an active hydrogen-containing component; An organic isocyanate component that reacts with the active hydrogen-containing component; A metal catalyst, preferably metal acetylacetonate; And a catalyst inhibitor effective to inhibit gelation of the curable composition at a temperature of 55 DEG C for at least 4.7 minutes, preferably at least 5 minutes. Processing the curable composition at a first temperature without curing the curable composition; And curing the curable composition to provide a polyurethane.

Embodiment 2: The method of producing a polyurethane according to embodiment 1, wherein the catalyst inhibitor is effective to inhibit gelation of the curable composition at a temperature of 70 DEG C for at least 2 minutes, preferably at least 3 minutes.

Embodiment 3: The inhibitor according to embodiment 1 or 2, wherein the inhibitor is a gel time at 70 DEG C which is 3 times longer, preferably at least 3.5 times longer, more preferably at least 4 times longer than the gel time of the same curable composition, ≪ / RTI > by weight of the polyurethane.

Embodiment 4: The method of any one of embodiments 1-3 wherein the step of processing the curable composition occurs at a first temperature of up to 120 캜, preferably from 40 to 120 캜, more preferably from 50 to 120 캜. ≪ / RTI >

Embodiment 5: The method of any one of modes 1 to 4, wherein processing the curable composition comprises moving the curable composition, molding the curable composition, or a combination comprising at least one of the foregoing. ≪ / RTI >

Embodiment 6: The method of any one of modes 1 to 5, wherein the curing step comprises raising the temperature of the curable composition to a second temperature effective to cure the curable composition.

Mode 7: The method according to any one of modes 1 to 3, wherein the step of curing the curable composition occurs at a second temperature of 40 to 120 캜, preferably 60 to 120 캜, more preferably 60 to 120 캜 , ≪ / RTI >

Embodiment 8: The curable composition according to embodiment 1, wherein the curable composition further comprises a surfactant to provide a polyurethane foam, preferably a frosted polyurethane foam, Wherein the composition further comprises a combination of at least one of loading, physically blowing, or chemically blowing the composition.

Embodiment 9: The catalyst inhibitor according to any one of embodiments 1 to 8, wherein the catalyst inhibitor is at least one selected from the group consisting of? -Diketone,? -Diketoamide,? -Ketoester,? -Diester,? -Dinitrile,? -Dialdehyde,? -Ketoaldehyde, crown ether, or a combination comprising at least one of the foregoing.

Embodiment 10: The catalyst inhibitor according to embodiment 9, wherein the catalyst inhibitor is dibenzoylmethane, 4,4,4-trifluoro-l, 3- phenyl-1,3-butanedione, N, N-diethyl-acetoacetamide, benzoylacetone, dimethyl isobutylmalonate, Diethyl isobutylmalonate, 3-ethyl-2,4-pentanedione, 3-chloro-2,4-pentanedione, Malononitrile, 18-crown-6, or a combination comprising at least one of the foregoing, preferably wherein the catalyst inhibitor is selected from the group consisting of dibenzoylmethane, 4,4,4-trifluoro- -1,3-butanedione, N, N-diethyl-acetoacetamide, or a combination comprising at least one of the foregoing.

Embodiment 11: The catalyst according to any one of modes 1 to 10, wherein the amount of the catalyst inhibitor is in the range of 5 to 5000 mol%, preferably 20 to 2000 mol%, more preferably 20 to 2000 mol%, based on the total moles of the metal catalyst, preferably metal acetylacetonate, , More preferably 50 to 1000 mol%, and still more preferably 100 to 1000 mol%.

12. The method of any one of embodiments 1-11, wherein the active hydrogen-containing component comprises at least one of a polyester polyol, a polyether polyol, a polycaprolactone, And a chain extender, preferably ethylene glycol, diethylene glycol, dipropylene glycol, 1,4-butanediol, 1,4-butanediol, At least one of 1,6-hexanediol, cyclohexane dimethanol, hydroquinone bis (2-hydroxyethyl) ether, ≪ / RTI > wherein the polyurethane comprises a combination comprising: < RTI ID = 0.0 >

(13) The process of any one of (1) to (12), wherein the organic isocyanate component is diphenylmethane-4,4'-diisocyanate, toluene diisocyanate, A prepolymer comprising at least one, a quasi-prepolymer comprising at least one of the foregoing, or a combination comprising at least one of the foregoing.

The process of any one of embodiments 1-13, wherein the metal catalyst is selected from the group consisting of aluminum acetylacetonate, barium acetylacetonate, cadmium acetylacetonate, calcium acetylacetonate, calcium acetylacetonate, cesium (III) acetylacetonate, chromium (III) acetylacetonate, cobalt (II) acetylacetonate, cobalt (III) acetylacetonate, copper (II) acetylacetonate, indium acetylacetonate, iron (II) acetylacetonate, manganese (III) acetylacetonate, neodymium acetylacetonate, manganese (II) acetylacetonate, iron (III) acetylacetonate, lanthanum acetylacetonate, lead Nickel (II) acetylacetonate, palladium (II) acetylacetonate, potassium acetylacetonate, At least one of the following materials is included: sodium acetylacetonate, sodium acetylacetonate, terbium acetylacetonate, titanium acetylacetonate, vanadium acetylacetonate, yttrium acetylacetonate, zinc acetylacetonate, zirconium acetylacetonate, , Preferably iron (III) acetylacetonate. ≪ Desc / Clms Page number 13 >

Embodiment 15: The production method of polyurethane according to any one of modes 1 to 14, wherein the metal catalyst comprises iron (III) acetylacetonate.

Embodiment 16: A polyurethane produced by the method of any one of embodiments 1 to 15.

Mode 17: The composition according to embodiment 16, wherein the composition is a polyurethane foam that is pre-loaded, water-blown, or physically blown, preferably mechanically-pruned, blown with water, Polyurethane.

Generally, the articles and methods described herein may alternatively, consist of, or consist essentially of any element or step disclosed herein. Articles and methods may be additionally or alternatively made or carried out so as to avoid or substantially avoid any element, step, or element that is not required to achieve the function or object of the claims of the invention.

The singular forms "a," an, "and" the " include plural referents unless the context clearly dictates otherwise. "Or" means "and / or." Unless specifically stated otherwise in the context, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. "Combinations" include blends, mixtures, alloys, reaction products, and the like. The values described herein include a tolerance range for a particular value as determined by one of ordinary skill in the art, which will depend in part on the manner in which the value is measured or determined, i. (For example, a range of "5 to 20% by weight" means that the range of "5 to 25% by weight" Point and all intermediate values). The wider range or the initiation of a particular group than the wider range is not intended to abandon a wider range or larger group.

All cited documents, patent applications and other references are incorporated herein by reference in their entirety. However, where the terms in this application contradict or conflict with the terms of the referenced references, the terms of the present application take precedence over the conflicting terms in the references contained therein.

While the present invention has been described in terms of several aspects and representative embodiments thereof, those skilled in the art will recognize that various changes and modifications can be made therein without departing from the scope of the invention. Likewise, additional features known in the art may be included. Also, although individual features of some aspects of the present invention may be discussed herein and may not be discussed in other aspects, it is to be understood that each individual feature of some aspects may be combined with features from one or more features or aspects of the other aspects It should be clear that

Claims (17)

As a method of producing a polyurethane,
The method comprises:
An active hydrogen-containing component; An organic isocyanate component that reacts with the active hydrogen-containing component; A metal catalyst, preferably metal acetylacetonate; And a catalyst inhibitor effective to inhibit gelation of the curable composition at a temperature of 55 DEG C for at least 4.7 minutes, preferably at least 5 minutes.
Processing the curable composition at a first temperature without curing the curable composition; And
And curing the curable composition to provide the polyurethane.
The method according to claim 1,
Wherein the catalyst inhibitor is effective to inhibit gelation of the curable composition at a temperature of 70 DEG C for at least 2 minutes, preferably at least 3 minutes.
3. The method according to claim 1 or 2,
Wherein said inhibitor is effective to provide a gel time at 70 DEG C that is no catalyst inhibitor but is three times longer, preferably at least 3.5 times longer, more preferably at least 4 times longer than the gel time of the same curable composition. Gt;
4. The method according to any one of claims 1 to 3,
Wherein the step of processing the curable composition takes place at a first temperature of up to 120 캜, preferably from 40 to 120 캜, more preferably from 50 to 120 캜.
5. The method according to any one of claims 1 to 4,
Wherein the step of processing the curable composition comprises moving the curable composition, molding the curable composition, or a combination comprising at least one of the foregoing.
6. The method according to any one of claims 1 to 5,
Wherein the curing step comprises raising the temperature of the curable composition to a second temperature effective to cure the curable composition.
4. The method according to any one of claims 1 to 3,
Wherein the step of curing the curable composition takes place at a second temperature of from 40 to 120 占 폚, preferably from 60 to 120 占 폚, more preferably from 60 to 120 占 폚.
The method according to claim 1,
The curable composition further comprises a surfactant to provide a polyurethane foam, preferably a mechanically frothed polyurethane foam, the method comprising the steps of: loading the curable composition; Or a combination comprising at least one of them. ≪ RTI ID = 0.0 > 18. < / RTI >
9. The method according to any one of claims 1 to 8,
The catalyst inhibitor may be selected from the group consisting of? -Diketones,? -Diketoamides,? -Ketoesters,? -Diesters,? -Dinitriles,? -Dialdehydes,? -Ketoaldehydes, crown ethers, And combinations comprising at least one of the foregoing.
10. The method of claim 9,
The catalyst inhibitor is selected from the group consisting of dibenzoylmethane, 4,4,4-trifluoro-1-phenyl-1,3-butanedione, N, N-diethyl-acetoacetamide, benzoylacetone, dimethyl isobutylmalonate, diethyl isobutylmalonate, 3- Ethyl-2,4-pentanedione, 3-chloro-2,4-pentanedione, malononitrile, 18 -Crown-6, or a combination comprising at least one of the foregoing, wherein the catalyst inhibitor is selected from the group consisting of dibenzoylmethane, 4,4,4-trifluoro-1-phenyl-1,3-butanedione, N, N-diethyl-acetoacetamide, or a combination comprising at least one of the foregoing.
11. The method according to any one of claims 1 to 10,
The amount of the catalyst inhibitor is in the range of 5 to 5000 mol%, preferably 20 to 2000 mol%, more preferably 50 to 1000 mol%, more preferably 5 to 5 mol%, based on the total molar amount of the metal catalyst, preferably metal acetylacetonate Is 100 to 1000 mol%.
12. The method according to any one of claims 1 to 11,
The active hydrogen-containing component may be selected from the group consisting of a polyester polyol, a polyether polyol, a polycaprolactone, or a combination comprising at least one of the foregoing, and a chain extender, Ethylene glycol, diethylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,6-hexanediol, , Cyclohexane dimethanol, hydroquinone bis (2-hydroxyethyl) ether, or a combination comprising at least one of the foregoing. Gt;
13. The method according to any one of claims 1 to 12,
Wherein the organic isocyanate component comprises at least one of diphenylmethane-4,4'-diisocyanate, toluene diisocyanate, a prepolymer containing at least one of the foregoing, A quasi-prepolymer, or a combination comprising at least one of the foregoing.
14. The method according to any one of claims 1 to 13,
The metal catalyst is selected from the group consisting of aluminum acetylacetonate, barium acetylacetonate, cadmium acetylacetonate, calcium acetylacetonate, cerium (III) acetylacetonate, chromium (III) acetylacetonate, cobalt (II) acetylacetonate, cobalt (III) acetylacetonate, copper (II) acetylacetonate, indium acetylacetonate, iron (II) acetylacetonate, manganese (II) acetylacetonate, manganese (III) acetylacetonate, neodymium acetylacetonate, nickel (II) acetylacetonate, palladium (II) Acetonate, potassium acetylacetonate, samarium acetylacetonate, cattle And combinations comprising at least one of the foregoing, preferably iron (III), acetylacetonate, terbium acetylacetonate, titanium acetylacetonate, vanadium acetylacetonate, yttrium acetylacetonate, zinc acetylacetonate, zirconium acetylacetonate, ) Acetylacetonate. ≪ / RTI >
15. The method according to any one of claims 1 to 14,
Wherein the metal catalyst comprises iron (III) acetylacetonate.
A polyurethane produced by the process of any one of claims 1 to 15.
17. The method of claim 16,
Wherein said composition is a polyurethane foam that is prefilled, water-blown, or physically blown, preferably mechanically-prilled, blown with water, or a combination thereof.

Images